Healthy Living

Is There Something Fishy About Fish Oil? New Study Links Supplements to Increased AF and Stroke Risk

Fish oil supplements, long celebrated for their omega-3 fatty acids and potential cardiovascular advantages, have recently come under scrutiny. A study published in the BMJ suggests that while these supplements may hold promise for individuals with pre-existing cardiovascular conditions, they could pose risks for the broader population.


Study Overview

The research, conducted as part of the UK Biobank project, analyzed a cohort of 415,737 participants aged 40-69 years, initially free of cardiovascular diseases. From January 2006 to December 2010, with follow-up until March 2021, the study examined the impact of fish oil supplement consumption on atrial fibrillation (AF), major adverse cardiovascular events, and mortality.


Key Findings

  1. Increased Risk for Some: Among the participants, 18,367 developed AF, 22,636 experienced major adverse cardiovascular events, and 22,140 died during the follow-up period. Notably, individuals without a history of heart disease who regularly consumed fish oil supplements faced a 13% higher risk of AF and a 5% greater risk of stroke. Women in this subgroup also exhibited a 6% higher likelihood of heart attack, stroke, or heart failure.
  2. Benefits for Others: Conversely, participants with pre-existing cardiovascular conditions appeared to benefit from regular fish oil supplementation. The study observed a 15% lower risk of progression from AF to severe cardiac issues and from heart failure to mortality.


Implications for Public Health

These findings paint a nuanced picture of fish oil supplements’ role in cardiovascular health. While they may carry risks for the general population, individuals with existing cardiovascular conditions could find them beneficial in preventing further adverse events.


Study Limitations

It’s crucial to acknowledge the study’s limitations. Being observational, it cannot establish causal relationships between fish oil supplement use and cardiovascular outcomes. Factors such as dosage, formulation, and lifestyle were not extensively documented, and the reliance on self-reported data introduces potential biases. Moreover, the study’s focus on UK adults may limit its applicability to other populations.



  • Consult Healthcare Providers: Prioritize discussions with healthcare providers before initiating or continuing fish oil supplements.
  • Consider Dietary Alternatives: Explore natural sources of omega-3 fatty acids, like fatty fish, nuts, and seeds, which may offer similar benefits with fewer associated risks.
  • Monitor Dosage: Adhere to recommended dosages and avoid excessive intake of fish oil supplements unless specifically advised by a healthcare professional.



The recent study on fish oil supplements underscores the importance of informed decision-making and individualized approaches to healthcare. While these supplements may hold promise for certain populations, their widespread use should be approached cautiously, with careful consideration of associated risks. Engaging with healthcare providers and maintaining a balanced lifestyle remain crucial to promoting cardiovascular health.

My advice to my patients is to get their omega-3 intake from natural food sources, such as enjoying a serving of salmon a couple of times a week and maintaining other healthy fats, such as olive oil. For those with raised triglyceride levels, discuss the intake of fish oil and the indication of prescription medication that may be appropriate.

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other anti-anginals

When first-line therapies for angina, such as beta blockers, calcium channel blockers, and nitrates, prove inadequate or are not well-tolerated, second-line therapies may be considered.
Perhexiline is a unique medication that enhances the heart's ability to utilize fatty acids for energy, reducing its reliance on oxygen and lowering oxygen demand. This action helps improve blood flow and alleviates chest pain in some patients with refractory angina.
Nicorandil is another second-line option with a dual mechanism of action. It opens potassium channels in smooth muscle cells, causing vasodilation and enhancing coronary blood flow. Additionally, nicorandil also stimulates nitric oxide release, further dilating blood vessels and reducing heart workload.
Trimetazidine is an anti-ischemic agent that improves cardiac efficiency by enhancing glucose metabolism and shifting the heart's energy production to a more oxygen-efficient process. As second-line therapies, these medications offer alternative approaches for managing angina in individuals who do not respond adequately to first-line treatments or those experiencing side effects from other medications.

lipid lowering therapies

Lipid-lowering therapies play a critical role in managing coronary artery disease (CAD), a condition characterized by the narrowing of blood vessels that supply the heart. Among the most commonly discussed and debated classes of medications are statins, which effectively reduce cholesterol levels and are widely prescribed to lower the risk of cardiovascular events. Alongside statins, other medications like ezetimibe, fibrates, and niacin are also utilized to target specific aspects of lipid metabolism, such as cholesterol absorption, triglyceride levels, and raising high-density lipoprotein (HDL) cholesterol. Additionally, the introduction of medications that inhibit PCSK9, an enzyme involved in cholesterol metabolism, has provided a promising new approach to further lower LDL cholesterol levels. These PCSK9 inhibitors, such as Repatha (evolocumab), have shown significant efficacy in reducing LDL cholesterol levels in patients with CAD, especially for those who may not respond well to traditional therapies.


Nitrates are widely used to treat angina and provide quick relief for chest pain. Commonly available in the form of sublingual sprays or tablets, patches, and long-acting tablets, nitrates work by dilating blood vessels, allowing for increased blood flow and reduced resistance. This dilation eases the heart's workload, leading to a decreased demand for oxygen and prompt alleviation of angina symptoms. Sublingual nitrates act rapidly and are often used to provide immediate relief during angina attacks, while patches and long-acting tablets are employed for preventive purposes. However, nitrates may cause side effects such as headaches, dizziness, and flushing, which usually subside over time.

calcium channel blockers

Calcium channel blockers, including amlodipine, felodipine, cardizem (diltiazem), and verapamil, are commonly prescribed for the treatment of angina. These medications work by inhibiting the influx of calcium into the muscle cells of the heart and blood vessels, leading to their relaxation. As a result, blood vessels widen, promoting improved blood flow and reduced blood pressure. In the context of angina, this relaxation decreases the heart's workload, lowering the demand for oxygen and alleviating chest pain. Calcium channel blockers offer a valuable treatment option for individuals with angina, but it is essential to be aware of potential side effects, which may include headaches, dizziness, flushing, and ankle swelling.

Beta blockers

Beta blockers, such as metoprolol, propranolol, atenolol, carvedilol, and bisoprolol, play a crucial role in treating angina. By blocking certain receptors in the heart, they effectively reduce heart rate and the force of contraction, thereby easing the heart's workload. This mechanism of action leads to a decreased demand for oxygen, making beta blockers highly effective in relieving chest pain associated with angina. As with any medication, it's important to consider potential side effects, including tiredness, worsened asthma, erectile dysfunction in some males, and more vivid dreams during sleep. Consult your healthcare provider to determine the suitability of beta blockers for managing your angina and overall heart health.

Anti-platelet Medications

Anti-platelet medications play a crucial role in preventing blood clot formation, reducing the risk of serious cardiovascular events such as heart attacks and strokes. Among the widely used anti-platelet drugs are aspirin, clopidogrel, and ticagrelor.

Aspirin: This well-known medication inhibits platelet activation, making it less likely for platelets to stick together and form clots. Aspirin is commonly used for primary and secondary prevention of heart attacks and strokes.

Clopidogrel: As a potent anti-platelet agent, clopidogrel works by blocking specific receptors on platelets, preventing them from aggregating. It is often prescribed to patients with acute coronary syndrome, those undergoing stent procedures, and for some cases of peripheral arterial disease.

Ticagrelor: Ticagrelor is another effective anti-platelet drug that works by inhibiting platelet activation. It is used in acute coronary syndrome, often given alongside aspirin to reduce the risk of heart-related events.